Python numpy 模块，iinfo() 实例源码

def test_rescaleData():
    dtypes = map(np.dtype, ('ubyte', 'uint16', 'byte', 'int16', 'int', 'float'))
    for dtype1 in dtypes:
        for dtype2 in dtypes:
            data = (np.random.random(size=10) * 2**32 - 2**31).astype(dtype1)
            for scale, offset in [(10, 0), (10., 0.), (1, -50), (0.2, 0.5), (0.001, 0)]:
                if dtype2.kind in 'iu':
                    lim = np.iinfo(dtype2)
                    lim = lim.min, lim.max
                else:
                    lim = (-np.inf, np.inf)
                s1 = np.clip(float(scale) * (data-float(offset)), *lim).astype(dtype2)
                s2 = pg.rescaleData(data, scale, offset, dtype2)
                assert s1.dtype == s2.dtype
                if dtype2.kind in 'iu':
                    assert np.all(s1 == s2)
                else:
                    assert np.allclose(s1, s2)

def test_rescaleData():
    dtypes = map(np.dtype, ('ubyte', 'uint16', 'byte', 'int16', 'int', 'float'))
    for dtype1 in dtypes:
        for dtype2 in dtypes:
            data = (np.random.random(size=10) * 2**32 - 2**31).astype(dtype1)
            for scale, offset in [(10, 0), (10., 0.), (1, -50), (0.2, 0.5), (0.001, 0)]:
                if dtype2.kind in 'iu':
                    lim = np.iinfo(dtype2)
                    lim = lim.min, lim.max
                else:
                    lim = (-np.inf, np.inf)
                s1 = np.clip(float(scale) * (data-float(offset)), *lim).astype(dtype2)
                s2 = pg.rescaleData(data, scale, offset, dtype2)
                assert s1.dtype == s2.dtype
                if dtype2.kind in 'iu':
                    assert np.all(s1 == s2)
                else:
                    assert np.allclose(s1, s2)

def to_best_type(array):
        '''Convert array to lowest possible bitrate.
        '''
        ui8 = np.iinfo(np.uint8)
        ui8 = ui8.max
        ui16 = np.iinfo(np.uint16)
        ui16 = ui16.max
        ui32 = np.iinfo(np.uint32)
        ui32 = ui32.max
        ui64 = np.iinfo(np.uint64)
        ui64 = ui64.max

        if array.max() <= ui64:
            new_type = np.uint64
        if array.max() <= ui32:
            new_type = np.uint32
        if array.max() <= ui16:
            new_type = np.uint16
        if array.max() <= ui8:
            new_type = np.uint8

        return array.astype(new_type)

def pack_samples(self, samples, dtype=None):
        """Pack samples into one integer per sample

        Store one sample in a single integer instead of a list of
        integers with length `len(self.nsoutdims)`. Example:

        >>> p = pauli_mpp(nr_sites=2, local_dim=2)
        >>> p.outdims
        (6, 6)
        >>> p.pack_samples(np.array([[0, 1], [1, 0], [1, 2], [5, 5]]))
        array([ 1,  6,  8, 35])

        """
        assert samples.ndim == 2
        assert samples.shape[1] == len(self.nsoutdims)
        samples = np.ravel_multi_index(samples.T, self.nsoutdims)
        if dtype not in (True, False, None) and issubclass(dtype, np.integer):
            info = np.iinfo(dtype)
            assert samples.min() >= info.min
            assert samples.max() <= info.max
            samples = samples.astype(dtype)
        return samples

def read(cls, filename):
        """
        Read an audio file (only wav is supported).

        Parameters
        ----------
        filename: string
            Path to the wav file.
        """
        sample_rate, samples = wavfile.read(filename)
        if samples.dtype==np.dtype('int16'):
            samples = samples.astype(_types.float_) / np.iinfo(np.dtype('int16')).min
        if len(samples.shape)==1:
            samples = samples.reshape((samples.shape[0],1))
        instance = cls(samples, sample_rate)
        return instance

def test_allclose(self):
        # Tests allclose on arrays
        a = np.random.rand(10)
        b = a + np.random.rand(10) * 1e-8
        self.assertTrue(allclose(a, b))
        # Test allclose w/ infs
        a[0] = np.inf
        self.assertTrue(not allclose(a, b))
        b[0] = np.inf
        self.assertTrue(allclose(a, b))
        # Test allclose w/ masked
        a = masked_array(a)
        a[-1] = masked
        self.assertTrue(allclose(a, b, masked_equal=True))
        self.assertTrue(not allclose(a, b, masked_equal=False))
        # Test comparison w/ scalar
        a *= 1e-8
        a[0] = 0
        self.assertTrue(allclose(a, 0, masked_equal=True))

        # Test that the function works for MIN_INT integer typed arrays
        a = masked_array([np.iinfo(np.int_).min], dtype=np.int_)
        self.assertTrue(allclose(a, a))

def test_respect_dtype_singleton(self):
        # See gh-7203
        for dt in self.itype:
            lbnd = 0 if dt is np.bool_ else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool_ else np.iinfo(dt).max + 1

            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertEqual(sample.dtype, np.dtype(dt))

        for dt in (np.bool, np.int, np.long):
            lbnd = 0 if dt is np.bool else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool else np.iinfo(dt).max + 1

            # gh-7284: Ensure that we get Python data types
            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertFalse(hasattr(sample, 'dtype'))
            self.assertEqual(type(sample), dt)

def test_dtype2(self, dtype):
        dtype = numpy.dtype(dtype)

        # randint does not support 64 bit integers
        if dtype in (numpy.int64, numpy.uint64):
            return

        iinfo = numpy.iinfo(dtype)
        size = (10000,)

        x = random.randint(iinfo.min, iinfo.max + 1, size, dtype)
        self.assertEqual(x.dtype, dtype)
        self.assertLessEqual(iinfo.min, min(x))
        self.assertLessEqual(max(x), iinfo.max)

        # Lower bound check
        with self.assertRaises(ValueError):
            random.randint(iinfo.min - 1, iinfo.min + 10, size, dtype)

        # Upper bound check
        with self.assertRaises(ValueError):
            random.randint(iinfo.max - 10, iinfo.max + 2, size, dtype)

def __init__(self, N=30, paired=False):
        """
        Parameters
        ----------
        N: int
            number of calls to average over.
        paired: boolean
            if paired is chosen the same series of random seeds is used for different x
        """
        self._N = int(N)
        self.paired = paired
        if self.paired:
            self.uint32max = np.iinfo(np.uint32).max 
            self.seeds = list(np.random.randint(0, self.uint32max, size=int(N)))
        # cache previous iterations
        self.cache = {}
        # number of evaluations
        self.nev = 0

def _calculate(self, X, y, categorical, metafeatures, helpers):
        occurrences = helpers.get_value("ClassOccurrences")

        min_value = np.iinfo(np.int64).max
        if len(y.shape) == 2:
            for i in range(y.shape[1]):
                for num_occurrences in occurrences[i].values():
                    if num_occurrences < min_value:
                        min_value = num_occurrences
        else:
            for num_occurrences in occurrences.values():
                if num_occurrences < min_value:
                    min_value = num_occurrences
        return float(min_value) / float(y.shape[0])


# aka default accuracy

def __init__(self, model, statistics_calc, backend, n_samples = 1000, seed = None):
        self.model = model
        self.statistics_calc = statistics_calc
        self.backend = backend
        self.rng = np.random.RandomState(seed)
        self.model.prior.reseed(self.rng.randint(np.iinfo(np.uint32).max, dtype=np.uint32)) 

        # main algorithm                 
        seed_arr = self.rng.randint(1, n_samples*n_samples, size=n_samples, dtype=np.int32)
        seed_pds = self.backend.parallelize(seed_arr)     

        sample_parameters_statistics_pds = self.backend.map(self._sample_parameter_statistics, seed_pds)
        sample_parameters_and_statistics = self.backend.collect(sample_parameters_statistics_pds)
        sample_parameters, sample_statistics = [list(t) for t in zip(*sample_parameters_and_statistics)]
        sample_parameters = np.array(sample_parameters)
        sample_statistics = np.concatenate(sample_statistics)

        self.coefficients_learnt = np.zeros(shape=(sample_parameters.shape[1],sample_statistics.shape[1]))
        regr = linear_model.LinearRegression(fit_intercept=True)
        for ind in range(sample_parameters.shape[1]):
            regr.fit(sample_statistics, sample_parameters[:,ind]) 
            self.coefficients_learnt[ind,:] = regr.coef_

def test_allclose(self):
        # Tests allclose on arrays
        a = np.random.rand(10)
        b = a + np.random.rand(10) * 1e-8
        self.assertTrue(allclose(a, b))
        # Test allclose w/ infs
        a[0] = np.inf
        self.assertTrue(not allclose(a, b))
        b[0] = np.inf
        self.assertTrue(allclose(a, b))
        # Test allclose w/ masked
        a = masked_array(a)
        a[-1] = masked
        self.assertTrue(allclose(a, b, masked_equal=True))
        self.assertTrue(not allclose(a, b, masked_equal=False))
        # Test comparison w/ scalar
        a *= 1e-8
        a[0] = 0
        self.assertTrue(allclose(a, 0, masked_equal=True))

        # Test that the function works for MIN_INT integer typed arrays
        a = masked_array([np.iinfo(np.int_).min], dtype=np.int_)
        self.assertTrue(allclose(a, a))

def test_respect_dtype_singleton(self):
        # See gh-7203
        for dt in self.itype:
            lbnd = 0 if dt is np.bool_ else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool_ else np.iinfo(dt).max + 1

            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertEqual(sample.dtype, np.dtype(dt))

        for dt in (np.bool, np.int, np.long):
            lbnd = 0 if dt is np.bool else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool else np.iinfo(dt).max + 1

            # gh-7284: Ensure that we get Python data types
            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertFalse(hasattr(sample, 'dtype'))
            self.assertEqual(type(sample), dt)

def read_window(window, src_url, mask_url=None, scale=1):
    tile_size = 256 * scale

    with rasterio.Env(CPL_VSIL_CURL_ALLOWED_EXTENSIONS='.vrt,.tif,.ovr,.msk'):
        src = get_source(src_url)

        # TODO read the data and the mask in parallel
        if mask_url:
            data = src.read(out_shape=(3, tile_size, tile_size), window=window)
            mask = get_source(mask_url)
            mask_data = mask.read(out_shape=(1, tile_size, tile_size), window=window)

            return np.concatenate((data, mask_data))
        else:
            if src.count == 4:
                # alpha channel present
                return src.read(out_shape=(4, tile_size, tile_size), window=window)
            else:
                # no alpha channel, create one
                # TODO use src.bounds as an implicit mask
                data = src.read(out_shape=(3, tile_size, tile_size), window=window)
                alpha = np.full((1, tile_size, tile_size), np.iinfo(data.dtype).max, data.dtype)

                return np.concatenate((data, alpha))

def read_window(window, src_url, mask_url=None, scale=1):
    tile_size = 256 * scale

    with rasterio.Env(CPL_VSIL_CURL_ALLOWED_EXTENSIONS='.vrt,.tif,.ovr,.msk'):
        src = get_source(src_url)

        # TODO read the data and the mask in parallel
        if mask_url:
            data = src.read(out_shape=(3, tile_size, tile_size), window=window)
            mask = get_source(mask_url)
            mask_data = mask.read(out_shape=(1, tile_size, tile_size), window=window)

            return np.concatenate((data, mask_data))
        else:
            if src.count == 4:
                # alpha channel present
                return src.read(out_shape=(4, tile_size, tile_size), window=window)
            else:
                # no alpha channel, create one
                # TODO use src.bounds as an implicit mask
                data = src.read(out_shape=(3, tile_size, tile_size), window=window)
                alpha = np.full((1, tile_size, tile_size), np.iinfo(data.dtype).max, data.dtype)

                return np.concatenate((data, alpha))

def run(n_seeds, n_jobs, _run, _seed):
    seed_list = check_random_state(_seed).randint(np.iinfo(np.uint32).max,
                                                  size=n_seeds)
    exps = []
    exps += [{'method': 'sgd',
              'step_size': step_size}
             for step_size in np.logspace(-3, 3, 7)]
    exps += [{'method': 'gram',
             'reduction': reduction}
            for reduction in [1, 4, 6, 8, 12, 24]]

    rundir = join(basedir, str(_run._id), 'run')
    if not os.path.exists(rundir):
        os.makedirs(rundir)

    Parallel(n_jobs=n_jobs,
             verbose=10)(delayed(single_run)(config_updates, rundir, i)
                         for i, config_updates in enumerate(exps))

def run(n_seeds, n_jobs, _run, _seed):
    seed_list = check_random_state(_seed).randint(np.iinfo(np.uint32).max,
                                                  size=n_seeds)
    exps = []
    exps += [{'method': 'sgd',
              'step_size': step_size}
             for step_size in np.logspace(-7, -7, 1)]
    exps += [{'method': 'gram',
              'reduction': reduction}
             for reduction in [12]]

    rundir = join(basedir, str(_run._id), 'run')
    if not os.path.exists(rundir):
        os.makedirs(rundir)

    Parallel(n_jobs=n_jobs,
             verbose=10)(delayed(single_run)(config_updates, rundir, i)
                         for i, config_updates in enumerate(exps))

def argmin(self, axis=None):
        """
        return a ndarray of the minimum argument indexer

        See also
        --------
        numpy.ndarray.argmin
        """

        i8 = self.asi8
        if self.hasnans:
            mask = self._isnan
            if mask.all():
                return -1
            i8 = i8.copy()
            i8[mask] = np.iinfo('int64').max
        return i8.argmin()

def test_allclose(self):
        # Tests allclose on arrays
        a = np.random.rand(10)
        b = a + np.random.rand(10) * 1e-8
        self.assertTrue(allclose(a, b))
        # Test allclose w/ infs
        a[0] = np.inf
        self.assertTrue(not allclose(a, b))
        b[0] = np.inf
        self.assertTrue(allclose(a, b))
        # Test all close w/ masked
        a = masked_array(a)
        a[-1] = masked
        self.assertTrue(allclose(a, b, masked_equal=True))
        self.assertTrue(not allclose(a, b, masked_equal=False))
        # Test comparison w/ scalar
        a *= 1e-8
        a[0] = 0
        self.assertTrue(allclose(a, 0, masked_equal=True))

        # Test that the function works for MIN_INT integer typed arrays
        a = masked_array([np.iinfo(np.int_).min], dtype=np.int_)
        self.assertTrue(allclose(a, a))

def find_bmu(self, vec):

        """Find the best matching unit (BMU) for a given vector.

        Args:           
            vec (np.array): The vector to match.

        Returns:            
            bmu (somNode): The best matching unit node.

        """

        minVal=np.iinfo(np.int).max
        for node in self.nodeList:
            dist=node.get_distance(vec)
            if dist < minVal:
                minVal=dist
                bmu=node
        return bmu

def test_allclose(self):
        # Tests allclose on arrays
        a = np.random.rand(10)
        b = a + np.random.rand(10) * 1e-8
        self.assertTrue(allclose(a, b))
        # Test allclose w/ infs
        a[0] = np.inf
        self.assertTrue(not allclose(a, b))
        b[0] = np.inf
        self.assertTrue(allclose(a, b))
        # Test all close w/ masked
        a = masked_array(a)
        a[-1] = masked
        self.assertTrue(allclose(a, b, masked_equal=True))
        self.assertTrue(not allclose(a, b, masked_equal=False))
        # Test comparison w/ scalar
        a *= 1e-8
        a[0] = 0
        self.assertTrue(allclose(a, 0, masked_equal=True))

        # Test that the function works for MIN_INT integer typed arrays
        a = masked_array([np.iinfo(np.int_).min], dtype=np.int_)
        self.assertTrue(allclose(a, a))

def test_int64_uint64_corner_case(self):
        # When stored in Numpy arrays, `lbnd` is casted
        # as np.int64, and `ubnd` is casted as np.uint64.
        # Checking whether `lbnd` >= `ubnd` used to be
        # done solely via direct comparison, which is incorrect
        # because when Numpy tries to compare both numbers,
        # it casts both to np.float64 because there is
        # no integer superset of np.int64 and np.uint64. However,
        # `ubnd` is too large to be represented in np.float64,
        # causing it be round down to np.iinfo(np.int64).max,
        # leading to a ValueError because `lbnd` now equals
        # the new `ubnd`.

        dt = np.int64
        tgt = np.iinfo(np.int64).max
        lbnd = np.int64(np.iinfo(np.int64).max)
        ubnd = np.uint64(np.iinfo(np.int64).max + 1)

        # None of these function calls should
        # generate a ValueError now.
        actual = mt19937.randint(lbnd, ubnd, dtype=dt)
        assert_equal(actual, tgt)

def test_respect_dtype_singleton(self):
        # See gh-7203
        for dt in self.itype:
            lbnd = 0 if dt is np.bool_ else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool_ else np.iinfo(dt).max + 1

            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertEqual(sample.dtype, np.dtype(dt))

        for dt in (np.bool, np.int, np.long):
            lbnd = 0 if dt is np.bool else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool else np.iinfo(dt).max + 1

            # gh-7284: Ensure that we get Python data types
            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertFalse(hasattr(sample, 'dtype'))
            self.assertEqual(type(sample), dt)

def test_respect_dtype_singleton(self):
        # See gh-7203
        for dt in self.itype:
            lbnd = 0 if dt is np.bool_ else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool_ else np.iinfo(dt).max + 1

            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertEqual(sample.dtype, np.dtype(dt))

        for dt in (np.bool, np.int, np.long):
            lbnd = 0 if dt is np.bool else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool else np.iinfo(dt).max + 1

            # gh-7284: Ensure that we get Python data types
            sample = self.rfunc(lbnd, ubnd, dtype=dt)
            self.assertFalse(hasattr(sample, 'dtype'))
            self.assertEqual(type(sample), dt)

def test_allclose(self):
        # Tests allclose on arrays
        a = np.random.rand(10)
        b = a + np.random.rand(10) * 1e-8
        self.assertTrue(allclose(a, b))
        # Test allclose w/ infs
        a[0] = np.inf
        self.assertTrue(not allclose(a, b))
        b[0] = np.inf
        self.assertTrue(allclose(a, b))
        # Test allclose w/ masked
        a = masked_array(a)
        a[-1] = masked
        self.assertTrue(allclose(a, b, masked_equal=True))
        self.assertTrue(not allclose(a, b, masked_equal=False))
        # Test comparison w/ scalar
        a *= 1e-8
        a[0] = 0
        self.assertTrue(allclose(a, 0, masked_equal=True))

        # Test that the function works for MIN_INT integer typed arrays
        a = masked_array([np.iinfo(np.int_).min], dtype=np.int_)
        self.assertTrue(allclose(a, a))

def _compute_asset_lifetimes(self):
        """
        Compute and cache a recarry of asset lifetimes.
        """
        equities_cols = self.equities.c
        buf = np.array(
            tuple(
                sa.select((
                    equities_cols.sid,
                    equities_cols.start_date,
                    equities_cols.end_date,
                )).execute(),
            ), dtype='<f8',  # use doubles so we get NaNs
        )
        lifetimes = np.recarray(
            buf=buf,
            shape=(len(buf),),
            dtype=[
                ('sid', '<f8'),
                ('start', '<f8'),
                ('end', '<f8')
            ],
        )
        start = lifetimes.start
        end = lifetimes.end
        start[np.isnan(start)] = 0  # convert missing starts to 0
        end[np.isnan(end)] = np.iinfo(int).max  # convert missing end to INTMAX
        # Cast the results back down to int.
        return lifetimes.astype([
            ('sid', '<i8'),
            ('start', '<i8'),
            ('end', '<i8'),
        ])

def append_data_column(ds, column):

    # Extend the dataset to fit the new data
    new_count = column.shape[0]
    existing_count = ds.shape[0]
    ds.resize((existing_count + new_count,))

    levels = get_levels(ds)

    if levels is not None:
        # update levels if we have new unique values
        if type(column.values) == p.Categorical:
            added_levels = set(column.values.categories) - set(levels)
        elif len(column) == 0:
            # Workaround for bug in pandas - get a crash in .unique() for an empty series
            added_levels = set([])
        else:
            added_levels = set(column.unique()) - set(levels)

        new_levels = list(levels)
        new_levels.extend(added_levels)

        # Check if the new categorical column has more levels
        # than the current bit width supports.
        # If so, rewrite the existing column data w/ more bits
        if len(new_levels) > np.iinfo(ds.dtype).max:
            new_dtype = pick_cat_dtype(len(new_levels))
            ds = widen_cat_column(ds, new_dtype)

        new_levels = np.array(new_levels, dtype=np.object)
        new_data = make_index_array(new_levels, column.values, ds.dtype)

        clear_levels(ds)
        create_levels(ds, new_levels)
    else:
        new_data = column

    # Append new data
    ds[existing_count:(existing_count + new_count)] = new_data

def compute_scale_for_cesium(coordmin, coordmax):
    '''
    Cesium quantized positions need to be in uint16
    This function computes the best scale to apply to coordinates
    to fit the range [0, 65535]
    '''
    max_int = np.iinfo(np.uint16).max
    delta = abs(coordmax - coordmin)
    scale = 10 ** -(math.floor(math.log1p(max_int / delta) / math.log1p(10)))
    return scale

def transform(self, pixels):
        data = pixels.data
        (count, height, width) = data.shape

        if 3 > count > 4:
            raise Exception("Source data must be 3 or 4 bands")

        if count == 4:
            raise Exception(
                "Variable opacity (alpha channel) not yet implemented")

        data *= np.iinfo(np.uint8).max

        rgb = np.ma.transpose(data.astype(np.uint8), [1, 2, 0])
        if data.mask.any():
            a = np.logical_and.reduce(~data.mask).astype(np.uint8) * 255
        else:
            a = np.full((rgb.shape[:-1]), 255, np.uint8)

            # Nearblack filtering for collar removal--partial, as edge values
            # will have been resampled in such a way that they don't retain
            # their crispness.
            # See https://stackoverflow.com/a/22631583 for neighborhood
            # filtering
            # sums = np.add.reduce(data)
            # threshold = 64
            # a = np.logical_and(sums > threshold, sums <
            #                    (255 * 3) - threshold).astype(np.uint8) * 255

        return PixelCollection(np.dstack((rgb, a)), pixels.bounds), 'RGBA'

def _nodata(dtype):
    if np.issubdtype(dtype, float):
        return np.finfo(dtype).min
    else:
        return np.iinfo(dtype).min

def _create_variables(self):
    if self.input_type.ndim != 0:
      raise TypeError('Embeddings take scalar inputs.')
    dtype = tf.as_dtype(self.input_type.dtype)
    if not dtype.is_integer: raise TypeError('Embeddings take integer inputs.')
    if dtype not in (tf.int32, tf.int64):  # only dtypes supported by tf.gather
      if np.iinfo(dtype.as_numpy_dtype).max > 2147483647:
         # pedantic future-proofing to handle hypothetical tf.uint64
        raise TypeError('cannot gather or upcast dtype %s' % dtype)
      self._cast = True
    else:
      self._cast = False
    self._weights = tf.get_variable(
        'weights', self._weights_shape, initializer=self._initializer,
        trainable=self._trainable)

def test_signed_integer_division_overflow(self):
        # Ticket #1317.
        def test_type(t):
            min = np.array([np.iinfo(t).min])
            min //= -1

        with np.errstate(divide="ignore"):
            for t in (np.int8, np.int16, np.int32, np.int64, np.int, np.long):
                test_type(t)

def test_shape_invalid(self):
        # Check that the shape is valid.
        max_int = np.iinfo(np.intc).max
        max_intp = np.iinfo(np.intp).max
        # Too large values (the datatype is part of this)
        assert_raises(ValueError, np.dtype, [('a', 'f4', max_int // 4 + 1)])
        assert_raises(ValueError, np.dtype, [('a', 'f4', max_int + 1)])
        assert_raises(ValueError, np.dtype, [('a', 'f4', (max_int, 2))])
        # Takes a different code path (fails earlier:
        assert_raises(ValueError, np.dtype, [('a', 'f4', max_intp + 1)])
        # Negative values
        assert_raises(ValueError, np.dtype, [('a', 'f4', -1)])
        assert_raises(ValueError, np.dtype, [('a', 'f4', (-1, -1))])

def test_min_int(self):
        # Could make problems because of abs(min_int) == min_int
        min_int = np.iinfo(np.int_).min
        a = np.array([min_int], dtype=np.int_)
        assert_(np.allclose(a, a))

def test_ldexp_overflow(self):
        # silence warning emitted on overflow
        with np.errstate(over="ignore"):
            imax = np.iinfo(np.dtype('l')).max
            imin = np.iinfo(np.dtype('l')).min
            assert_equal(ncu.ldexp(2., imax), np.inf)
            assert_equal(ncu.ldexp(2., imin), 0)

def test_iter_too_large():
    # The total size of the iterator must not exceed the maximum intp due
    # to broadcasting. Dividing by 1024 will keep it small enough to
    # give a legal array.
    size = np.iinfo(np.intp).max // 1024
    arr = np.lib.stride_tricks.as_strided(np.zeros(1), (size,), (0,))
    assert_raises(ValueError, nditer, (arr, arr[:, None]))
    # test the same for multiindex. That may get more interesting when
    # removing 0 dimensional axis is allowed (since an iterator can grow then)
    assert_raises(ValueError, nditer,
                  (arr, arr[:, None]), flags=['multi_index'])

def test_export_record(self):
        dt = [('a', 'b'),
              ('b', 'h'),
              ('c', 'i'),
              ('d', 'l'),
              ('dx', 'q'),
              ('e', 'B'),
              ('f', 'H'),
              ('g', 'I'),
              ('h', 'L'),
              ('hx', 'Q'),
              ('i', np.single),
              ('j', np.double),
              ('k', np.longdouble),
              ('ix', np.csingle),
              ('jx', np.cdouble),
              ('kx', np.clongdouble),
              ('l', 'S4'),
              ('m', 'U4'),
              ('n', 'V3'),
              ('o', '?'),
              ('p', np.half),
              ]
        x = np.array(
                [(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
                    asbytes('aaaa'), 'bbbb', asbytes('   '), True, 1.0)],
                dtype=dt)
        y = memoryview(x)
        assert_equal(y.shape, (1,))
        assert_equal(y.ndim, 1)
        assert_equal(y.suboffsets, EMPTY)

        sz = sum([np.dtype(b).itemsize for a, b in dt])
        if np.dtype('l').itemsize == 4:
            assert_equal(y.format, 'T{b:a:=h:b:i:c:l:d:q:dx:B:e:@H:f:=I:g:L:h:Q:hx:f:i:d:j:^g:k:=Zf:ix:Zd:jx:^Zg:kx:4s:l:=4w:m:3x:n:?:o:@e:p:}')
        else:
            assert_equal(y.format, 'T{b:a:=h:b:i:c:q:d:q:dx:B:e:@H:f:=I:g:Q:h:Q:hx:f:i:d:j:^g:k:=Zf:ix:Zd:jx:^Zg:kx:4s:l:=4w:m:3x:n:?:o:@e:p:}')
        # Cannot test if NPY_RELAXED_STRIDES_CHECKING changes the strides
        if not (np.ones(1).strides[0] == np.iinfo(np.intp).max):
            assert_equal(y.strides, (sz,))
        assert_equal(y.itemsize, sz)

def test_basic(self):
        dts = list(zip(['i1', 'i2', 'i4', 'i8',
                   'u1', 'u2', 'u4', 'u8'],
                  [np.int8, np.int16, np.int32, np.int64,
                   np.uint8, np.uint16, np.uint32, np.uint64]))
        for dt1, dt2 in dts:
            assert_equal(iinfo(dt1).min, iinfo(dt2).min)
            assert_equal(iinfo(dt1).max, iinfo(dt2).max)
        self.assertRaises(ValueError, iinfo, 'f4')

def test_unsigned_max(self):
        types = np.sctypes['uint']
        for T in types:
            assert_equal(iinfo(T).max, T(-1))

def test_iinfo_repr(self):
        expected = "iinfo(min=-32768, max=32767, dtype=int16)"
        assert_equal(repr(np.iinfo(np.int16)), expected)

def test_instances():
    iinfo(10)
    finfo(3.0)

def test_int_raise_behaviour(self):
        def overflow_error_func(dtype):
            np.typeDict[dtype](np.iinfo(dtype).max + 1)

        for code in 'lLqQ':
            assert_raises(OverflowError, overflow_error_func, code)

def test_diophantine_overflow():
    # Smoke test integer overflow detection
    max_intp = np.iinfo(np.intp).max
    max_int64 = np.iinfo(np.int64).max

    if max_int64 <= max_intp:
        # Check that the algorithm works internally in 128-bit;
        # solving this problem requires large intermediate numbers
        A = (max_int64//2, max_int64//2 - 10)
        U = (max_int64//2, max_int64//2 - 10)
        b = 2*(max_int64//2) - 10

        assert_equal(solve_diophantine(A, U, b), (1, 1))

def test_min_int(self):
        a = np.array([np.iinfo(np.int_).min], dtype=np.int_)
        # Should not raise:
        assert_allclose(a, a)

def test_randint_range(self):
        # Test for ticket #1690
        lmax = np.iinfo('l').max
        lmin = np.iinfo('l').min
        try:
            random.randint(lmin, lmax)
        except:
            raise AssertionError

def test_rng_zero_and_extremes(self):
        for dt in self.itype:
            lbnd = 0 if dt is np.bool_ else np.iinfo(dt).min
            ubnd = 2 if dt is np.bool_ else np.iinfo(dt).max + 1
            tgt = ubnd - 1
            assert_equal(self.rfunc(tgt, tgt + 1, size=1000, dtype=dt), tgt)
            tgt = lbnd
            assert_equal(self.rfunc(tgt, tgt + 1, size=1000, dtype=dt), tgt)
            tgt = (lbnd + ubnd)//2
            assert_equal(self.rfunc(tgt, tgt + 1, size=1000, dtype=dt), tgt)

def test_random_integers_max_int(self):
        # Tests whether random_integers can generate the
        # maximum allowed Python int that can be converted
        # into a C long. Previous implementations of this
        # method have thrown an OverflowError when attempting
        # to generate this integer.
        actual = np.random.random_integers(np.iinfo('l').max,
                                           np.iinfo('l').max)
        desired = np.iinfo('l').max
        np.testing.assert_equal(actual, desired)

def test_random_integers_deprecated(self):
        with warnings.catch_warnings():
            warnings.simplefilter("error", DeprecationWarning)

            # DeprecationWarning raised with high == None
            assert_raises(DeprecationWarning,
                          np.random.random_integers,
                          np.iinfo('l').max)

            # DeprecationWarning raised with high != None
            assert_raises(DeprecationWarning,
                          np.random.random_integers,
                          np.iinfo('l').max, np.iinfo('l').max)

def test_poisson_exceptions(self):
        lambig = np.iinfo('l').max
        lamneg = -1
        assert_raises(ValueError, np.random.poisson, lamneg)
        assert_raises(ValueError, np.random.poisson, [lamneg]*10)
        assert_raises(ValueError, np.random.poisson, lambig)
        assert_raises(ValueError, np.random.poisson, [lambig]*10)

def dtype_min_max(dtype):
    '''Get the min and max value for a numeric dtype'''
    if np.issubdtype(dtype, np.integer):
        info = np.iinfo(dtype)
    else:
        info = np.finfo(dtype)
    return info.min, info.max